1. Field of the Invention
The present invention relates to a single wheel caster apparatus for supporting a plow for maintaining an airport runway.
More specifically, the present invention relates to a single wheel caster apparatus for an airport plow for removing snow and ice from a runway.
2. Information Disclosure Statement
Many international airports cater to over a million passengers a year and every effort is made to maintain air transportation even under inclement weather conditions.
Accordingly, airports are supplied with airport plows for removing snow and ice from runways.
Usually an airport plow is mounted to the front of a massive truck or tractor, such plows having a width of as much as 35 ft. The plow is capable of being offset or reversed relative to the truck so that as the truck and plow combination move along the runway, snow and ice are lifted from the runway and ejected sideways from the path of travel.
Because of the considerable weight of the plow, dual wheel casters have been provided adjacent to each side of the plow for supporting the moldboard and ancillary framework.
In the prior art airport plows as stated hereinbefore, a dual wheel caster has been secured to each end of the base of the plow apparatus. However, in each caster, the dual wheels actually share the same vertical pivot axis which extends between the respective tires. Also, the dual wheels are designed to rotate through 360 degrees about such vertical axis with the axles or more usually the common axle of the dual wheels moving through a horizontal plane. Accordingly, such movement of the axle or axles creates a strong tendency for the prior art dual wheel casters to severely wobble during movement thereof. Such wobbling of the dual wheels occurs because as the load to one of the wheel changes, the other wheel over corrects and the process repeats itself. Therefore, after a limited amount of operational time, the dual wheel wobble causes excessive wear to the tires and rapid failure thereof.
The present invention overcomes the aforementioned wheel wobble syndrome by the provision of a unique single wheel caster arrangement in which the entire weight of the apparatus is supported by means of single wheel casters disposed adjacent to the lateral sides of the plow.
Therefore, a primary objective of the present invention is to provide a single wheel caster apparatus for an airport plow that overcomes the aforementioned problems associated with the prior art arrangements and which makes a considerable contribution to the art of maintaining airport runways.
Another object of the present invention is the provision of a single wheel caster apparatus supported by a pair of forks which rotate relative to a tube having a spring detent mechanism therein for controlling wobble of the wheel while permitting reversing of the plow.
Other objects and advantages of the present invention will be readily apparent to those skilled in the art by a consideration of the detailed description contained hereinafter taken in conjunction with the annexed drawings.